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          <th colspan="3" align="center">Dbc::get()</th>
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    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="dbcget"></a>Dbc::get()</h2>
          </div>
        </div>
      </div>
      <pre class="programlisting">#include &lt;db_cxx.h&gt;

int
Dbc::get(Dbt *key, Dbt *data, u_int32_t flags);

int
Dbc::pget(Dbt *key, Dbt *pkey, Dbt *data, u_int32_t flags); </pre>
      <p>
         The <code class="methodname">Dbc::get()</code> method retrieves key/data pairs from the
         database.  The address and length of the key are returned in the
         object to which <span class="bold"><strong>key</strong></span> refers (except
         for the case of the DB_SET flag, in which the <span class="bold"><strong>key</strong></span> object is unchanged), and the address and
         length of the data are returned in the object to which <span class="bold"><strong>data</strong></span> refers.
    </p>
      <p>
         When called on a cursor opened on a database that has been made into a
         secondary index using the 
         <a class="xref" href="dbassociate.html" title="Db::associate()">Db::associate()</a>  method, the
         <code class="methodname">Dbc::get()</code> and <code class="methodname">Dbc::pget()</code> 
         methods return the key from the
         secondary index and the data item from the primary database. In
         addition, the <code class="methodname">Dbc::pget()</code> method returns the key from the
         primary database.  In databases that are not secondary indices, the
         <code class="methodname">Dbc::pget()</code> method will always fail.
    </p>
      <p>
         Modifications to the database during a sequential scan will be
         reflected in the scan; that is, records inserted behind a cursor will
         not be returned while records inserted in front of a cursor will be
         returned.
    </p>
      <p>
         In Queue and Recno databases, missing entries (that is, entries that
         were never explicitly created or that were created and then deleted)
         will be skipped during a sequential scan.
    </p>
      <p>
         Unless otherwise specified, the <code class="methodname">Dbc::get()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
     </p>
      <p>
         If <code class="methodname">Dbc::get()</code> fails for any reason, the state of the cursor will
         be unchanged.
     </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6167896"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6203160"></a>key</h4>
              </div>
            </div>
          </div>
          <p>
                  The key <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>  operated on.
             </p>
          <p>
                 If <a class="link" href="dbt.html#dbt_DB_DBT_PARTIAL">DB_DBT_PARTIAL</a>
                 is set for the Dbt used for this parameter,
                 and if the <span class="bold"><strong>flags</strong></span> parameter 
                 is set to
                 <a class="link" href="dbcget.html#dbcget_DB_GET_BOTH">DB_GET_BOTH</a>,
                 <a class="link" href="dbcget.html#dbcget_DB_GET_BOTH_RANGE">DB_GET_BOTH_RANGE</a>,
                 <a class="link" href="dbcget.html#dbcget_DB_SET">DB_SET</a>, or
                 <a class="link" href="dbcget.html#dbcget_DB_SET_RECNO">DB_SET_RECNO</a>,
                 then this method will fail and return <code class="literal">EINVAL</code>.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6207616"></a>pkey</h4>
              </div>
            </div>
          </div>
          <p>
                 The return key from the primary database.  
                 If
                  <a class="link" href="dbt.html#dbt_DB_DBT_PARTIAL">DB_DBT_PARTIAL</a>
                  is set for the Dbt used for this parameter,
                 then this method will fail and return <code class="literal">EINVAL</code>.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6173912"></a>data</h4>
              </div>
            </div>
          </div>
          <p>
                  The data <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>  operated on.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6199728"></a>flags</h4>
              </div>
            </div>
          </div>
          <p>
                  The <span class="bold"><strong>flags</strong></span> parameter must be set to
                  one of the following values:
             </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p><a id="dbcget_DB_CURRENT"></a>
                          <code class="literal">DB_CURRENT</code>
                     </p>
                <p>
                        Return the key/data pair to which the cursor refers. 
                     </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_KEYEMPTY" class="olink">DB_KEYEMPTY</a>
                         if DB_CURRENT is set and the cursor key/data pair
                         was deleted.
                     </p>
              </li>
              <li>
                <p><a id="dbcget_DB_FIRST"></a>
                          <code class="literal">DB_FIRST</code>
                    </p>
                <p>
                         The cursor is set to refer to the first key/data
                         pair of the database, and that pair is returned.
                         If the first key has duplicate values, the first
                         data item in the set of duplicates is returned.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_FIRST flag will ignore any keys that exist but
                         were never explicitly created by the application,
                         or were created and later deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_FIRST is set and the database is empty.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_GET_BOTH"></a>
                          <code class="literal">DB_GET_BOTH</code>
                    </p>
                <p>
                        Move the cursor to the specified key/data pair of
                        the database. The cursor is positioned to a
                        key/data pair if both the key and data match the
                        values provided on the key and data parameters.
                    </p>
                <p>
                         In all other ways, this flag  is identical to the 
                         <a class="link" href="dbcget.html#dbcget_DB_SET">DB_SET</a>
                         flag.
                    </p>
                <p>
                         When used with
                         <code class="methodname">Dbc::pget()</code> on a
                         secondary index handle, both the secondary and
                         primary keys must be matched by the secondary and
                         primary key item in the database.  It is an error
                         to use the DB_GET_BOTH flag with the
                         <code class="methodname">Dbc::get()</code> version
                         of this method and a cursor that has been opened on a secondary index
                         handle.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_GET_BOTH_RANGE"></a>
                          <code class="literal">DB_GET_BOTH_RANGE</code>
                    </p>
                <p>
                        Move the cursor to the specified key/data pair of the
                        database. The key parameter must be an exact match with a
                        key in the database. The data item retrieved is the item in
                        a duplicate set that is the smallest value which is greater than or equal
                        to the value provided by the data parameter (as determined by the comparison
                        function). If this flag is specified on a database
                        configured without sorted duplicate support, the behavior
                        is identical to the <code class="literal">DB_GET_BOTH</code> flag. Returns the datum
                        associated with the given key/data pair.
                     </p>
                <p>
                         In all other ways, this flag  is identical to the 
                         <a class="link" href="dbcget.html#dbcget_DB_GET_BOTH">DB_GET_BOTH</a>
                         flag.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_GET_RECNO"></a>
                          <code class="literal">DB_GET_RECNO</code>
                    </p>
                <p>
                         Return the record number associated with the cursor.  The record
                         number will be returned in <span class="bold"><strong>data</strong></span>, as
                         described in <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>.  The
                         <span class="bold"><strong>key</strong></span> parameter is ignored.
                    </p>
                <p>
                         For DB_GET_RECNO to be specified, the underlying database must be of
                         type Btree, and it must have been created with the 
                         <a class="link" href="dbset_flags.html#dbset_flags_DB_RECNUM">DB_RECNUM</a>
                         flag.
                    </p>
                <p>
                         When called on a cursor opened on a database that has been made into a
                         secondary index, the <code class="methodname">Dbc::get()</code> and 
                         <code class="methodname">Dbc::pget()</code> methods return the record 
                         number of the primary database in <span class="bold"><strong>data</strong></span>.  
                         In addition, the <code class="methodname">Dbc::pget()</code>
                         method returns the record number of the secondary index in <span class="bold"><strong>pkey</strong></span>.  If either underlying database is not of
                         type Btree or is not created with the 
                         <a class="link" href="dbset_flags.html#dbset_flags_DB_RECNUM">DB_RECNUM</a>
                         flag, the out-of-band record number of 0 is returned.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_JOIN_ITEM"></a>
                          <code class="literal">DB_JOIN_ITEM</code>
                    </p>
                <p>
                         Do not use the data value found in all of the cursors as a lookup key
                         for the primary database, but simply return it in the key parameter
                         instead. The data parameter is left unchanged.
                    </p>
                <p>
                         For DB_JOIN_ITEM to be specified, the underlying cursor must have been
                         returned from the <a class="xref" href="dbjoin.html" title="Db::join()">Db::join()</a>  method.
                    </p>
                <p>
                        This flag is not supported for Heap databases.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_LAST"></a>
                         <code class="literal">DB_LAST</code>
                    </p>
                <p>
                         The cursor is set to refer to the last key/data pair of the database,
                         and that pair is returned.  If the last key has duplicate values, the
                         last data item in the set of duplicates is returned.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_LAST flag will ignore any keys that exist but
                         were never explicitly created by the application,
                         or were created and later deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_LAST is set and the database is empty.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_NEXT"></a>
                         <code class="literal">DB_NEXT</code>
                    </p>
                <p>
                         If the cursor is not yet initialized, DB_NEXT is identical to
                         DB_FIRST.  Otherwise, the cursor is moved to the next key/data pair of
                         the database, and that pair is returned.  In the presence of duplicate
                         key values, the value of the key may not change.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_NEXT flag will skip any keys that exist but
                         were never explicitly created by the application,
                         or those that were created and later deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_NEXT is set and the cursor is already on the
                         last record in the database.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_NEXT_DUP"></a>
                          <code class="literal">DB_NEXT_DUP</code>
                    </p>
                <p>
                         If the next key/data pair of the database is a duplicate data record
                         for the current key/data pair, the cursor is moved to the next
                         key/data pair of the database, and that pair is returned.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_NEXT_DUP is set and the next key/data pair
                         of the database is not a duplicate data record for
                         the current key/data pair.
                    </p>
                <p>
                        If using a Heap database, this flag results in this
                        method returning
                        <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_NEXT_NODUP"></a>
                          <code class="literal">DB_NEXT_NODUP</code>
                    </p>
                <p>
                         If the cursor is not yet initialized, DB_NEXT_NODUP is identical to
                         DB_FIRST.  Otherwise, the cursor is moved to the next non-duplicate
                         key of the database, and that key/data pair is returned.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_NEXT_NODUP flag will ignore any keys that exist
                         but were never explicitly created by the
                         application, or those that were created and later
                         deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_NEXT_NODUP is set and no non-duplicate
                         key/data pairs exist after the cursor position in
                         the database.
                    </p>
                <p>
                        If using a Heap database, this flag is identical to
                        the <code class="literal">DB_NEXT</code> flag.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_PREV"></a>
                         <code class="literal">DB_PREV</code>
                    </p>
                <p>
                         If the cursor is not yet initialized, DB_PREV is identical to DB_LAST.
                          Otherwise, the cursor is moved to the previous key/data pair of the
                         database, and that pair is returned.  In the presence of duplicate key
                         values, the value of the key may not change.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_PREV flag will skip any keys that exist but
                         were never explicitly created by the application,
                         or those that were created and later deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_PREV is set and the cursor is already on the
                         first record in the database.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_PREV_DUP"></a>
                          <code class="literal">DB_PREV_DUP</code>
                    </p>
                <p>
                         If the previous key/data pair of the database is a duplicate data
                         record for the current key/data pair, the cursor is moved to the
                         previous key/data pair of the database, and that pair is returned.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_PREV_DUP is set and the previous key/data
                         pair of the database is not a duplicate data
                         record for the current key/data pair.
                    </p>
                <p>
                        If using a Heap database, this flag results in this
                        method returning
                        <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_PREV_NODUP"></a>
                          <code class="literal">DB_PREV_NODUP</code>
                    </p>
                <p>
                         If the cursor is not yet initialized,
                         DB_PREV_NODUP is identical to DB_LAST.  Otherwise,
                         the cursor is moved to the previous non-duplicate
                         key of the database, and that key/data pair is
                         returned.
                    </p>
                <p>
                         If the database is a Queue or Recno database,
                         <code class="methodname">Dbc::get()</code> using the
                         DB_PREV_NODUP flag will ignore any keys that exist
                         but were never explicitly created by the
                         application, or those that were created and later
                         deleted.
                    </p>
                <p>
                         The <code class="methodname">Dbc::get()</code> method
                         will return 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a>
                         if DB_PREV_NODUP is set and no non-duplicate
                         key/data pairs exist before the cursor position in
                         the database.
                    </p>
                <p>
                        If using a Heap database, this flag is identical to
                        the <code class="literal">DB_PREV</code> flag.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_SET"></a>
                         <code class="literal">DB_SET</code>
                    </p>
                <p>
                         Move the cursor to the specified key/data pair of the database, and
                         return the datum associated with the given key.
                    </p>
                <p>
                        The <code class="methodname">Dbc::get()</code> method will return 
                        <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a> 
                        if DB_SET is set and no matching keys are found.
                        The <code class="methodname">Dbc::get()</code> method
                        will return 
                        <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_KEYEMPTY" class="olink">DB_KEYEMPTY</a>
                        if DB_SET is set and the database is a Queue or
                        Recno database, and the specified key exists, but
                        was never explicitly created by the application or
                        was later deleted. In the presence of duplicate key
                        values, <code class="methodname">Dbc::get()</code> will
                        return the first data item for the given key.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_SET_RANGE"></a>
                          <code class="literal">DB_SET_RANGE</code>
                    </p>
                <p>
                        Move the cursor to the specified key/data pair of the
                        database. In the case of the Btree access method, the key
                        is returned as well as the data item and the returned
                        key/data pair is the smallest key greater than or equal to
                        the specified key (as determined by the Btree comparison
                        function), permitting partial key matches and range
                        searches.
                    </p>
                <p>
                        In all other ways the behavior of this flag is the same
                        as the 
                        <a class="link" href="dbcget.html#dbcget_DB_SET">DB_SET</a> flag.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_SET_RECNO"></a>
                          <code class="literal">DB_SET_RECNO</code>
                    </p>
                <p>
                         Move the cursor to the specific numbered record of
                         the database, and return the associated key/data
                         pair.  The <span class="bold"><strong>data</strong></span>
                         field of the specified 
                         <span class="bold"><strong>key</strong></span> must be a pointer
                         to a memory location from which a
                         <code class="literal">db_recno_t</code>  may be read, as
                         described in 
                         <a class="link" href="dbt.html" title="Chapter 4.  The Dbt Handle">Dbt</a>.  This memory
                         location will be read to determine the record to
                         be retrieved.
                    </p>
                <p>
                         For DB_SET_RECNO to be specified, the underlying database must be of
                         type Btree, and it must have been created with the 
                         <a class="link" href="dbset_flags.html#dbset_flags_DB_RECNUM">DB_RECNUM</a>
                         flag.
                    </p>
              </li>
            </ul>
          </div>
          <p>
                 In addition, the following flags may be set by bitwise inclusively
                 <span class="bold"><strong>OR</strong></span>'ing them into the <span class="bold"><strong>flags</strong></span> parameter:
            </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p>
                          <code class="literal">DB_IGNORE_LEASE</code>
                    </p>
                <p>
                        This flag is relevant only when using a replicated
                        environment.
                    </p>
                <p>
                         Return the data item irrespective of the state of
                         master leases.  The item will be returned under
                         all conditions: if master leases are not
                         configured, if the request is made to a client, if
                         the request is made to a master with a valid
                         lease, or if the request is made to a master
                         without a valid lease.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_READ_COMMITTED"></a>
                          <code class="literal">DB_READ_COMMITTED</code>
                    </p>
                <p>
                         Configure a transactional get operation to have degree 2 isolation
                         (the read is not repeatable).
                    </p>
              </li>
              <li>
                <p>
                          <code class="literal">DB_READ_UNCOMMITTED</code>
                    </p>
                <p>
                         Database items read during a transactional call will have degree 1
                         isolation, including modified but not yet committed data.  Silently
                         ignored if the 
                         <a class="link" href="dbopen.html#dbopen_DB_READ_UNCOMMITTED">DB_READ_UNCOMMITTED</a> 
                         flag was not specified when the underlying database was opened.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_MULTIPLE"></a>
                             <code class="literal">DB_MULTIPLE</code>
                    </p>
                <p>
                         Return multiple data items in the <span class="bold"><strong>data</strong></span> parameter.
                    </p>
                <p>
                         In the case of Btree or Hash databases, duplicate data items for the
                         current key, starting at the current cursor position, are entered into
                         the buffer.  Subsequent calls with both the DB_NEXT_DUP and
                         DB_MULTIPLE flags specified will return additional duplicate data
                         items associated with the current key or 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a> 
                         if there are no additional duplicate data items to
                         return.  Subsequent calls with both the DB_NEXT
                         and DB_MULTIPLE flags specified will return
                         additional duplicate data items associated with
                         the current key or if there are no additional
                         duplicate data items will return the next key and
                         its data items or 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a> 
                         if there are no additional keys in the database.
                    </p>
                <p>
                         In the case of Queue, Recno, or Heap databases,
                         data items starting at the current cursor position
                         are entered into the buffer.  The record number
                         (or the RID, in the case of Heap) of
                         the first record will be returned in the 
                         <span class="bold"><strong>key</strong></span> parameter.
                         For Queue and Recno, the record number of each
                         subsequent returned record must be calculated from
                         this value.  For Heap databases, the RID of
                         subsequent returned records cannot be known. Subsequent
                         calls with the DB_MULTIPLE flag specified will
                         return additional data items or 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a> 
                         if there are no additional data items to return.
                    </p>
                <p>
                         The buffer to which the <span class="bold"><strong>data</strong></span>
                         parameter refers must be provided from user memory (see 
                         <a class="link" href="dbt.html#dbt_DB_DBT_USERMEM">DB_DBT_USERMEM</a> ). 
                         The buffer must be at least as large as the page size of the
                         underlying database, aligned for unsigned integer access, and be a
                         multiple of 1024 bytes in size.  If the buffer size is insufficient,
                         then upon return from the call the size field of the <span class="bold"><strong>data</strong></span> parameter will have been set to an
                         estimated buffer size, and the error DB_BUFFER_SMALL is returned. 
                         (The size is an estimate as the exact size needed may not be known
                         until all entries are read.  It is best to initially provide a
                         relatively large buffer, but applications should be prepared to resize
                         the buffer as necessary and repeatedly call the method.)
                    </p>
                <p>
                         The multiple data items can be iterated over using the 
                         
                         <span>
                             <a class="xref" href="dbmultipledataiterator.html" title="DbMultipleDataIterator">DbMultipleDataIterator</a> class.
                        </span>
                    </p>
                <p>
                         The DB_MULTIPLE flag may only be used with the DB_CURRENT, DB_FIRST,
                         DB_GET_BOTH, DB_GET_BOTH_RANGE, DB_NEXT, DB_NEXT_DUP, DB_NEXT_NODUP,
                         DB_SET, DB_SET_RANGE, and DB_SET_RECNO options.  The DB_MULTIPLE flag
                         may not be used when accessing databases made into secondary indices
                         using the <a class="xref" href="dbassociate.html" title="Db::associate()">Db::associate()</a>  method.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_MULTIPLE_KEY"></a>
                          <code class="literal">DB_MULTIPLE_KEY</code>
                    </p>
                <p>
                         Return multiple key and data pairs in the <span class="bold"><strong>data</strong></span> parameter.
                    </p>
                <p>
                         Key and data pairs, starting at the current cursor position, are
                         entered into the buffer.  Subsequent calls with both the DB_NEXT and
                         DB_MULTIPLE_KEY flags specified will return additional key and data
                         pairs or 
                         <a href="../../programmer_reference/program_errorret.html#program_errorret.DB_NOTFOUND" class="olink">DB_NOTFOUND</a> 
                         if there are no additional key and data items to return.
                    </p>
                <p>
                         In the case of Btree, Hash or Heap databases, the multiple key and data
                         pairs can be iterated over using the 
                         
                         <span>
                             <a class="xref" href="dbmultiplekeydataiterator.html" title="DbMultipleKeyDataIterator">DbMultipleKeyDataIterator</a> class.
                        </span>
                    </p>
                <p>
                         In the case of Queue or Recno databases,
                         the multiple record number and data pairs can be
                         iterated over using the 
                         
                         <span>
                             <a class="xref" href="dbmultiplerecnodataiterator.html" title="DbMultipleRecnoDataIterator">DbMultipleRecnoDataIterator</a> class.
                        </span>
                    </p>
                <p>
                         The buffer to which the <span class="bold"><strong>data</strong></span>
                         parameter refers must be provided from user memory (see 
                         <a class="link" href="dbt.html#dbt_DB_DBT_USERMEM">DB_DBT_USERMEM</a> ). 
                         The buffer must be at least as large as the page size of the
                         underlying database, aligned for unsigned integer access, and be a
                         multiple of 1024 bytes in size.  If the buffer size is insufficient,
                         then upon return from the call the size field of the <span class="bold"><strong>data</strong></span> parameter will have been set to an
                         estimated buffer size, and the error DB_BUFFER_SMALL is returned. 
                         (The size is an estimate as the exact size needed may not be known
                         until all entries are read.  It is best to initially provide a
                         relatively large buffer, but applications should be prepared to resize
                         the buffer as necessary and repeatedly call the method.)
                    </p>
                <p>
                         The DB_MULTIPLE_KEY flag may only be used with the DB_CURRENT,
                         DB_FIRST, DB_GET_BOTH, DB_GET_BOTH_RANGE, DB_NEXT, DB_NEXT_DUP,
                         DB_NEXT_NODUP, DB_SET, DB_SET_RANGE, and DB_SET_RECNO options.  The
                         DB_MULTIPLE_KEY flag may not be used when accessing databases made
                         into secondary indices using the 
                         <a class="xref" href="dbassociate.html" title="Db::associate()">Db::associate()</a>  method.
                    </p>
              </li>
              <li>
                <p><a id="dbcget_DB_RMW"></a>
                         <code class="literal">DB_RMW</code>
                    </p>
                <p>
                         Acquire write locks instead of read locks when doing the read, if
                         locking is configured.  Setting this flag can eliminate deadlock
                         during a read-modify-write cycle by acquiring the write lock during
                         the read part of the cycle so that another thread of control acquiring
                         a read lock for the same item, in its own read-modify-write cycle,
                         will not result in deadlock.
                    </p>
              </li>
            </ul>
          </div>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6283416"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
             The <code class="methodname">Dbc::get()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6291480"></a><span>DbMemoryException or </span>DB_BUFFER_SMALL</h4>
              </div>
            </div>
          </div>
          <p>
                The requested item could not be returned due to undersized buffer.
            </p>
          <p>
                <a class="xref" href="dbmemory.html" title="DbMemoryException">DbMemoryException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_BUFFER_SMALL</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6288496"></a><span>DbDeadlockException or </span>DB_LOCK_DEADLOCK</h4>
              </div>
            </div>
          </div>
          <p>
                A transactional database environment operation was selected to resolve
                a deadlock.
            </p>
          <p>
                <a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_LOCK_DEADLOCK</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6201488"></a><span>DbLockNotGrantedException or </span>DB_LOCK_NOTGRANTED</h4>
              </div>
            </div>
          </div>
          <p>
                A Berkeley DB Concurrent Data Store database environment configured
                for lock timeouts was unable to grant a lock in the allowed time.
            </p>
          <p>
                You attempted to open a database handle that is configured
                for no waiting exclusive locking, but the exclusive lock could not be
                immediately obtained. See
                <a class="xref" href="dbset_lk_exclusive.html" title="Db::set_lk_exclusive()">Db::set_lk_exclusive()</a>
                for more information.
            </p>
          <p>
                <a class="xref" href="dblocknotgranted.html" title="DbLockNotGrantedException">DbLockNotGrantedException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_LOCK_NOTGRANTED</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6127128"></a> <span>DbRepHandleDeadException or</span> DB_REP_HANDLE_DEAD</h4>
              </div>
            </div>
          </div>
          <p>
                When a client synchronizes with the master, it is possible for committed
                transactions to be rolled back. This invalidates all  the database and cursor
                handles opened in the replication environment. Once this occurs, an attempt to use
                such a handle will 
                <span>
                    throw a <a class="xref" href="dbrephandledead.html" title="DbRepHandleDeadException">DbRepHandleDeadException</a> (if
                    your application is configured to throw exceptions), or 
                </span>
                return <code class="literal">DB_REP_HANDLE_DEAD</code>.
                The application will need to discard the handle and open a new one in order to
                continue processing.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6218328"></a>DB_REP_LEASE_EXPIRED</h4>
              </div>
            </div>
          </div>
          <p>
                The operation failed because the site's replication master lease has expired.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6216376"></a><span>DbDeadlockException or </span>DB_REP_LOCKOUT</h4>
              </div>
            </div>
          </div>
          <p>
                The operation was blocked by client/master synchronization.
            </p>
          <p>
                <a class="xref" href="dbdeadlock.html" title="DbDeadlockException">DbDeadlockException</a> is thrown if
                your Berkeley DB API is configured to throw exceptions.
                Otherwise, <code class="literal">DB_REP_LOCKOUT</code> is returned.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6197752"></a>DB_SECONDARY_BAD</h4>
              </div>
            </div>
          </div>
          <p>
                A secondary index references a nonexistent primary key.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6202088"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
              If the DB_CURRENT, DB_NEXT_DUP or DB_PREV_DUP flags were
              specified and the cursor has not been initialized; the
              <code class="methodname">Dbc::pget()</code> method was called with
              a cursor that does not refer to a secondary index; or if an
              invalid flag value or parameter was specified.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6289776"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
            <a class="link" href="dbc.html" title="Chapter 3.  The Dbc Handle">Dbc</a>  
        </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6201616"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
             <a class="xref" href="dbc.html#dbclist" title="Database Cursors and Related Methods">Database Cursors and Related Methods</a> 
        </p>
      </div>
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